Josephus Problem

Thats no appian related question, is it ;)?

No just wanted to try using appian. Whether is it possible using expressuin rules or not?

You can implement recursive and iterative algorithms. So, the answer is: Yes!

sure it is ;)
looping functions might be your friend :)
a!forEach is one of them
https://docs.appian.com/suite/help/23.2/fnc_looping_a_foreach.html 

a!localVariables(
  local!makeArray: a!forEach(
    items: enumerate(ri!number) + 1,
    expression: fv!item
  ),
  local!resultArray,
  local!position: 1,
  a!forEach(
      items: local!makeArray,
      expression:
      {
        local!position+1,
        mod(local!position,length(fv!item)),
        remove(local!resultArray,local!position)
      }       
   )
)

I tried this code but not able to get the possible solution. If you find any possible please help me with this. Thanks in advance 

Is this some sort of exam question?

Yeah its a puzzle problem. You can refer this - https://www.geeksforgeeks.org/puzzle-100-people-in-a-circle-with-gun-puzzle/

i was just trying to implement using appian.

As Appian follows a functional approach, you cannot modify variables during runtime. You line 14 will not work.

Make this recursive, or use the reduce() function. It allows you to modify data across iterations.

appian.rocks/.../

This is my example with a recursive rule to solve the puzzle (#73).

As always, make sure to save recursive rules before testing.

/* rule!chris_test_kc_recur(
      list (Number Array, 1+enumerate(100))
      index (Number, 1)
   )
*/

if(
  count(ri!list)<=1,
  index(ri!list,1,null),
  a!localVariables(
    local!removeIndex: if(
      ri!index=count(ri!list),
      1,
      if(
        ri!index>count(ri!list),
        2,
        ri!index+1
      )
    ),
    local!list: remove(ri!list,local!removeIndex),
    rule!chris_test_kc_recur(
      list: local!list,
      index: local!removeIndex
    )
  )
)

can you please share me the code rule!chris_test_kc_recur? That would be helpful